coolant temp reading-PL or gauge?

[longbedGTs]

Between the coolant temp in Powerlogger vs the Autometer gauge, there is about a 15 degree difference. Which do you think is more trustworthy? The Autometer gauge/sending unit is of unknown age, FWIW. It's an electric gauge.

edit* The reading in powerlogger is the higher one. Gauge shows about 170ish warmed up. PL shows about 185-190

 

[grass doctor]

Between the coolant temp in Powerlogger vs the Autometer gauge, there is about a 15 degree difference. Which do you think is more trustworthy? The Autometer gauge/sending unit is of unknown age, FWIW. It's an electric gauge.

edit* The reading in powerlogger is the higher one. Gauge shows about 170ish warmed up. PL shows about 185-190

data feed from SM/powerlogger are notorious for being off... an actual gauge wired directly into sensor is best ...from what ive read

 

[Buckshot G/N]

Have seen this B4 ,PL is more accurate. Electrical gauge usually run a tad cooler which at a cruising speed, there more accurate when you in stop a go traffic and engine is running hotter.

 

[Chuck Leeper]

Depends somewhat on the sensor locations...

 

[Ttype6]

PL shows about 185-190

What is the temperature rating of your thermostat?

 

[Jerryl]

Just had this conversation a week ago.
On the car in my discussion, the sensors were both in the intake manifold, 8 inches apart.

The accuracy of a *real* GM sensor potentially has major legal implications. The aftermarket gage does not in any way.

You have to be able to trust the GM sensor as it controls fueling and timing in some applications, plus the coolant fans. If you can't trust it, find a way (ice water AND boiling water) to read the range. Voltage, pin corrosion, old wiring all diminish the accuracy.

 

[grass doctor]

Just had this conversation a week ago.
On the car in my discussion, the sensors were both in the intake manifold, 8 inches apart.

The accuracy of a *real* GM sensor has potential major legal implications. The aftermarket gage does not in any way.

You have to be able to trust the GM sensor as it controls fueling and timing in some applications, plus the coolant fans. If you can't trust it, find a way (ice water AND boiling water) to read the range. Voltage, pin corrosion, old wiring all diminish the accuracy.

but why are changing avatars on me like KC87's dirty drawers ...im sure you saw him at the soccer field today ...smelling LMAO

 

[mikes86ttop]

VDO gauge with avc dash is always 10-15* higher than the scanmaster/powerlogger readings on my car.... Mike

 

[Jerryl]

VDO gauge with avc dash is always 10-15* higher than the scanmaster/powerlogger readings on my car.... Mike

Correct.

 

[longbedGTs]

What is the temperature rating of your thermostat?

Unknown. I assumed it was a 160 when I was going by the Autometer gauge, but after noticing that the PL shows in the high 180s, I question it. Time to pull it out and check. Kinda figured the PO would have put a 160 in since the car came with so many high dollar mods, but who knows... Slowly but surely working out all the bugs in this car. Twas somewhat of a basket case...a neglected one.

 

[Buckshot G/N]

I have never had 160 stat run a true 160 temp my experience a 160 stat usually runs 180 to 190 in normal condition. If was a betting man I would say a 160 stat is what you have in housing.

 

[vacuum 6]

What is the temperature rating of your thermostat?

Yup that’s the way to verify. [emoji1360]

 

[grass doctor]

my 160 stat runs around 170 according to my SM ...on a stock set up car ...well very close to stock car

 

[Chuck Leeper]

I have never had 160 stat run a true 160 temp my experience a 160 stat usually runs 180 to 190 in normal condition. If was a betting man I would say a 160 stat is what you have in housing.

Just my $.02
A. A stock GN system was never designed to run at 160*.
B. A 160* stat only controls the minimum opening temp.
C. Many stats are just cracking open, at the rated temp. I've seen many that are at 5-10, even 20* higher, when fully open.
D. A lot of other conditions affect the op temp. Dirty, 30 yr old water jackets, rads w/ 3" of lime crud in the bottom, corroded core tubes.
Heat cycles affect the integrity of the solder joints connecting the tubes to the fins. As this happens, heat rejection declines.{ Same thing happens to the intercooler}.
E. A 30 y/o plastic fan, likely has the blades flattening out, reducing cfm. The electric motor at 30 y/o doesn't help.
And, no less important, we rely on a system designed to cool a 200HP engine, that's asked to put out 500....
Bottom line 180* works fine.

Back under my rock....

 

[Ttype6]

Unknown. I assumed it was a 160 when I was going by the Autometer gauge, but after noticing that the PL shows in the high 180s, I question it. Time to pull it out and check. Kinda figured the PO would have put a 160 in since the car came with so many high dollar mods, but who knows... Slowly but surely working out all the bugs in this car. Twas somewhat of a basket case...a neglected one.

I would bet that it is 180.

 

[Ttype6]

my 160 stat runs around 170 according to my SM ...on a stock set up car ...well very close to stock car

My heavily modified does the same. If the car runs hotter,the cooling system is not keeping up.

 

[captndave737]

I have a 180 deg tstat. My gauge reading and Sportsman reading are the same using different senders. I never had a power logger ithe the stock ECM. The fans are programed to come on at 190 and go off at 185. The car stays at 182-185 on the highway regardles of the OAT. 185-195 in traffic. Alradaco radiator, dual fans that only run on high (wiring changes) and a boxed in radiator.

 

[mikestertwo]

My VDO gauge and Powerlogger read within a few degrees of each other(I have the AVC dash). I would find out what thermostat is in the engine. Start the car from cold and watch the gauge and powerlogger readings. Typically the water temperature will overshoot above the thermostat rating about ten degrees then drop close to the thermostat rating as it warms up. A 160* thermostat typically will raise the water temperature to something in the 170-175* range then drop. A 180* thermostat will typically go to around 190* water temperature then drop. See which reading runs closer to the thermostat rating and that's the one I would trust. Of course this is assuming the thermostat is good.

 

[grass doctor]

also ...IIRC Erics's chips bring the fan on @ 165 ...

 

[longbedGTs]

Just to update for search purposes...it had a 180 in it. Now with the 160, it stays right at 165.
Also, there's still a 15deg difference between the gauge and PL. I can live with that.